Zend Server will be installed on the bundled Apache web server which
listens on port 10088 by default. This can be set to another port by
editing your Apache configuration file at
/usr/local/zend/apache2/conf/httpd.conf and changing the value of the
directive Listen.

So if you want Zend Server on port 80 just make change described above.

Changes in /etc/hosts that you described couldn't work - in hosts file you can just map IPs to hostnames.

Another solution will be creating some redirections on firewall using iptables, but for me it will be overkill...